"The winning photo shows a poignant, compassionate moment, the human consequence of an enormous event, an event that is still going on," jury chair Aidan Sullivan, of Getty Images, said in a statement. "We might never know who this woman is, cradling an injured relative, but together they become a living image of the courage of ordinary people that helped create an important chapter in the history of the Middle East."

Jury member Joel Sartore told National Geographic News, "Most, if not all, of the judges also liked the fact that the photo showed the consequences of war in a compassionate way. It is hopeful. It shows one human being taking care of another human being.

"It's a simple picture that spoke to us on a lot of levels, and we were really moved by it," said Sartore, a contributing photographer for National Geographic magazine. (The National Geographic Society owns both National Geographic magazine and National Geographic News.)

The World Press Photo Contest is the world's largest annual news-photography contest. For 2011 an international team of judges evaluated 101,254 images from 5,247 individual photographers of 124 nationalities.

—Brian Handwerk

Photograph courtesy Samuel Aranda, Corbis/NYT/World Press Photo

First Prize: Nature, Singles

In a desperate search for seabird eggs, a polar bear ventures into steep terrain above the ocean at Ostrova Oranskie, Russia, in June 2011. Marooned by melting sea ice, the bear is seen deprived of its usual prey—seals—in Jenny E. Ross's picture, which was named best single photograph in the "Nature" category.

Jury member Joel Sartore said, "Not only was this a beautiful picture in its own right, but it's showing new behavior, driven by climate change, that, as far as we know, had not been photographed before—and it was done very well."

According to jury member Sartore, "We just liked the fact that is was a fun look at a culture—kind of a campy look at the bar scene in Sochi. Once in a while we just picked a great image that made us smile."

Photograph courtesy Rob Hornstra, Sochi Project/World Press Photo

Second Prize: Sports, Singles

Irish photographer Ray McManus was on hand to capture the rugby action as Old Belvedere battled Blackrock in a driving Dublin rain in February 2011.

"You wouldn't generally know that you have taken a picture like that at the time," McManus told Irish sports website The Score. "You just go and do your work. I think I just got back into the car and transmitted some of the photos back to the office."

Shooting what was later titled "Scrum Half" was just another day's work, he added, but seeing the image honored in the World Press Photo Contest was "probably the best day of my career." (Also see "Gaelic Football, Hurling are Irish Passions.")

Jury member Sartore said, "It has kind of a painting quality to it. It's a common scene and an everyday moment that has a lot of atmosphere and really captures a mood—we were big on mood."

Photograph courtesy Ray McManus, Sportsfile/World Press Photo

First Prize: Daily Life, Singles

A portrait of North Korean founder Kim Il Sung appears to be the only thing deemed worthy of electric light in a cluster of Pyongyang buildings pictured in October 2011.

Though Kim died almost two decades ago, North Korea's constitution recognizes him as the nation's "eternal president." His son, Kim Jong Il, ruled the country until his own death in December 2011—not long after Damir Sagolj of Bosnia and Herzegovina had taken this picture.

"We thought this was a very powerful image that made a strong statement on what things are like in North Korea. It's a little slice of daily life, and it looks pretty stark," Sartore said. "It really suggests that, when you have a dictatorship, this is where it leads you—and it's not a good place."

Nearly half of all Yemeni women begin married life as child brides—including these girls posing with their husbands outside the mountain village of Hajjah Hajjah in June 2010. Tahani (in pink) married her husband, Majed, at age six. He was 25.

"This image is extremely powerful and a [great] use of photography to try to point out social ills or problems in society and shed a light on a very important issue," Sartore said. "It was done extremely well, and getting this kind of image of these subjects really took a lot of work."

Iranian-born actress Mellica Mehraban grew up in Denmark but returned to her native country in 2011 to play the villain in the dramatic filmFox Hunting. The government-approved script required the 27-year-old to demonstrate her character's love for the male lead—without ever touching him or telling him her feelings.

Mehraban's expressiveness also shone through in Laerke Posselt's image. "It's a very haunting picture," Sartore said. "Sometimes you can't say why a picture evokes a certain mood or emotion, but to us, this one was the most powerful of all the single-entry portraits that we had."

"This whole frame is perfectly filled with peak action," Sartore said. "Even the sky has people in it.

"It's a great frame, and the photographer was right there making sure it was composed well, even while those guys were under fire and running for their lives. That showed a lot of bravery and a lot of courage under fire."

"It's an unknown world," Peter said of the still largely unexplored cave during a lecture at National Geographic's Washington, D.C., headquarters in March.

"I knew these were the biggest passages we know of in the world, so how should I photograph it? How will I light it?" (See more of Peter's pictures of the "infinite" cave.)

Contest jury member Sartore said, "This was an epic story, and we liked the way the photographer put people in the space, so you can see how huge these caves are. It's also a lovely technical job lighting a big underground space that's as dark as dark can be."

Photograph by Carsten Peter, National Geographic

First Prize: Daily Life, Stories

Marcos (89) leads his wife of 65 years, Monica, into the couple's Buenos Aires living room in one of a series of images examining Alzheimer's disease called "Never Let You Go." Marcos has cared for his wife full-time since she was diagnosed with Alzheimer's in 2007.

"This shows people that you don't have to have some war in a far away land" to win a photo prize, Sartore said.

"There are good stories around us everyday. This is something that happens in our own backyards, thought through well and told with compassion."

Photograph courtesy Alejandro Kirchuk, World Press Photo

First Prize: Nature, Stories

A female rhinoceros (left)—her horn long since stolen by chainsaw-wielding poachers—meets a male in Tugela Private Game Reserve in South Africa in November 2010. Photographer Brent Stirton captured the image, part of a winning series, while on assignment for the March 2012 issue of National Geographic magazine. (See more rhino pictures from the assignment.)

Soaring demand from middle- and upper-class Asians has made rhino horn more valuable than gold—and cost South Africa alone more than 400 rhinos during 2011, according to World Press Photo.

"Brent's pictures were incredible," Sartore said. "He followed the story all the way from seeing rhinos in the field and the effects of poaching there to going into the courts to see horn traffickers at trial. He went all the way to China to watch the consumption of the horns in drinks and powders.

Egyptians react to President Hosni Mubarak's February 10, 2011, announcement that he would not immediately resign, despite widespread protests. The next day Mubarak resigned after three decades as Egypt's leader.

Italian Alex Maoli's image "was a nearly perfect picture of the anger that people were feeling when Mubarak would not step down," Sartore said.

"We loved the fact that it had almost theatrical lighting, soft and off to one side. It was one of our favorites from the entire contest."

Chieko Matsukawa pulls a treasure from the ruins of her Higashimatsushima, Japan, home in April 2011—her daughter's certificate of graduation. The earthquake and tsunami that rocked her region on March 11, 2011, cost half a million people their homes and more than 15,000 their lives.

"But this image," part of Yasuyoshi Chiba's "Aftermath of the Tsunami" series, "showed a moment of hope amid all the destruction," Sartore said.

"It kind of shows the human spirit, and we tried to find some moments that spoke to how resilient people are and how they can find little moments of hope or compassion or humor—anything that helps humanity overcome the obstacles that we see in many of these news events."